The born in stay in social class

 Upon reflection I think what the USA had against slavery was the concept the one could be born into slavery and needed the permission of another to be free,

That is "classism" The idea that one is born into and must stay in a social class. Ok. For Euros perhaps; but we had said "men are born free" The very concept of born social class stank in the nose of most Americans. That is why , I think, they would not let the South leave as long as they had slaves and even if it took a war, and it did, they were going to end it. It is not that the people of the North in 1861 believed in what we call "diversity" they did not as a whole. But the nation of 1861 was not the nation of 1789. The nation was tied together by press, rail, and telegraph. People of the mid 19 century knew, and knowing,they were not having the born in your class..stay in your class system in America.